The Correct Answer is: (C) Lysosome

Explanation:

Lysosomes are membrane-bound organelles found in animal cells that contain digestive enzymes. Their primary function is to break down cellular waste, damaged organelles, and foreign substances, making them the recycling centers of the cell.

Lysosomes also play a crucial role in cellular defense by digesting harmful pathogens and are often referred to as “suicidal bags” because they can self-destruct a damaged or dying cell through autolysis.

Information Booster:

• Intracellular Digestion: They help digest food particles and cellular debris, maintaining cellular health.
• Autophagy (Self-eating Process): Lysosomes remove old and damaged organelles, recycling useful components.
• Defense Mechanism: Helps destroy harmful bacteria and viruses that enter the cell.
• pH Environment: Lysosomes maintain a highly acidic environment (pH ~5), essential for enzyme activity.

Additional Information:

• Ribosome: Responsible for protein synthesis.
• Mitochondrion: Known as the powerhouse of the cell, producing ATP (energy).
• Nucleus: Controls genetic material (DNA) and cell functions,

Given:

Rice bought at ₹50/kg = let quantity be x kg

Rice bought at ₹55/kg = 100 kg

Selling price of the mixture = ₹60/kg

Profit earned = ₹1500

Solution:

Total quantity = x + 100

Total SP = 60(x + 100)

Profit = SP – CP = ₹1500

60(x + 100) - (50x + 5500) = 1500

60x + 6000 - 50x - 5500 = 1500

10x + 500 = 1500

10x = 1000

x = 100

100 kg of rice was purchased at ₹50 per kg.

Correct Answer:D. Snail

Explanation:

Many species of snails are hermaphrodites, meaning they have both male and female reproductive organs. Some snails can change their gender during their lifetime depending on environmental conditions and reproductive needs. This ability allows them to adapt and increase reproductive success.

Information Booster:

• Protandric Hermaphrodites: Some snails start as males and later transition to females (e.g., slipper snails).
• Simultaneous Hermaphrodites: Some snails function as both male and female at the same time (e.g., land snails).
• Snails reproduce by exchanging sperm with other snails or self-fertilizing in some species.
• Other animals that can change gender include clownfish, wrasses, and some starfishes.

Additional Information:

• Ascaris (A): A parasitic roundworm that has separate sexes (dioecious), no gender change.
• Humans (B): Humans have fixed biological sexes and cannot naturally change gender.
• Nereis (C): A type of marine worm (polychaete) with separate sexes, no gender change ability.

The Correct Answer is: (b) Solenoid

Explanation:

A solenoid is a long coil of many circular turns of insulated copper wire, wound tightly in the shape of a cylinder. When an electric current passes through a solenoid, it produces a magnetic field similar to that of a bar magnet.

The strength of the magnetic field inside the solenoid depends on the number of turns per unit length, the current passing through it, and the nature of the core material placed inside the solenoid.

Information Booster:

• The direction of the magnetic field in a solenoid can be determined using Ampere’s Right-Hand Rule.
• Solenoids are widely used in devices like electromagnets, electric bells, relays, and transformers.
• The magnetic field outside a solenoid is weak, while inside, it is strong and uniform.
• Increasing the number of turns of the coil enhances the strength of the magnetic field.
• Solenoids play a crucial role in various industrial applications, including MRI machines, automotive starters, and inductors.

Additional Information:

• Circular coil – A single loop or a few turns of wire in a circular shape, producing a weaker and non-uniform magnetic field.
• Straight conductor – A single wire carrying current that generates a circular magnetic field around it, as described by Oersted’s experiment.
• Toroid – A solenoid bent into a circular ring shape, often used in electrical transformers and inductors to confine the magnetic field.

The correct answer is: (c) Yen

Explanation:

• The official currency of Japan is the Yen (¥), which is abbreviated as JPY. The yen is one of the most traded currencies in the world and plays a significant role in the global economy.
• It was introduced in 1871 during the Meiji era as part of the modernization and standardization of Japan’s currency system.

Information Booster:

• Yen is subdivided into 100 sen, but the sen is rarely used.

• The currency code for the yen is JPY.

• Yen is the third-most-traded currency in the world, after the U.S. Dollar and Euro.

Additional Information:

• Won – Won is the currency of South Korea.

• Yuan – Yuan is the currency of China.

Given:

​11, 14, 17,24, 31, 34, 37, 44 ?

Logic: ​The differences follow a repeating pattern of 3, 3, 7, 7

Let's break it down with the step-by-step additions:

11 + 3 = 14

14 + 3 = 17

17 + 7 = 24

24 + 7 = 31

31 + 3 = 34

34 + 3 = 37

37 + 7 = 44

44 + 7 = 51

So, The next number in the series is (44 + 7) = 51.

Thus, the correct option is: (b)

Given:

2018

Spain: 120 visas

Portugal: 180 visas

2019

Spain: 100 visas

Portugal: 160 visas

2020

Spain: 80 visas

Portugal: 60 visas

Formula Used:

Ratio = Total visas issued in 2018 : Visas issued to Portugal in 2020

Solution:

Total visas issued in 2018

Total visas in 2018 = 120 (Spain) + 180 (Portugal) = 300

Visas issued to Portugal in 2020

Visas for Portugal in 2020 = 60

Calculate the ratio

Ratio = 300 : 60

5 : 1

Given:

20 ÷ 5 of 4 × 8 + 6 ÷ 24 of 3 × 48 - 6 ÷ 18 × 9

Formula Used:

BODMAS

Solution:

20 ÷ 5 of 4 × 8 + 6 ÷ 24 of 3 × 48 - 6 ÷ 18 × 9

= 20 ÷ 20 × 8 + 6 ÷ 72 × 48 - 6 ÷ 18 × 9

= 8 + 4 - 3

= 12 - 3

= 9

Thus, the correct option is (c) 9

Given:

Principal amount becomes 3 times in 5 years at compound interest.

Formula Used:

Compound Interest Formula:

Where:

A = Amount after n years

P = Principal amount

r = Annual interest rate (%)

n = Time period (years)

Solution:

Compare exponents:

n = 10 years

Alternate Method:

​The correct answer is (a) Litmus paper

Explanation:

Litmus paper is a natural acid-base indicator that changes color based on the pH of a solution:

• In acidic solutions (pH < 7) → Litmus paper turns red.
• In basic solutions (pH > 7) → Litmus paper turns blue.

It is derived from lichens and is commonly used in laboratories to quickly determine whether a substance is acidic or basic.

Information Booster:

• Other Acid-Base Indicators & Their Color Changes:
  • Phenolphthalein: Colorless in acid, pink in base.
  • Methyl Orange: Red in acid, yellow in base.
  • Bromothymol Blue: Yellow in acid, blue in base.
• Universal Indicator: A mixture of indicators that shows different colors at different pH values.